Lift truck



April 2, 1940. A. M. BARRETT LIFT TRUCK Filed July 3, 1936 2 Sheets-Sheet l April 2, 1940. A. M.. BARRETT 2,195,658

LIFT TRUCK Filed July s, 1935 I 2- Sheets-Sheet 2 Patented Apr. 2, 1940.

UNITED STATES PATENT OFF-ICE.

'Arthur' M. BarrettJWinnetka, I111, assignor 'to' Barrett-Cravens Company, Chicago, 111., a;

corporation of Illinois Application Julya, 193G,- Serial'No. 88, 913

' 16 Claims (01. 254-10) This invention relates to'lift trucks, and more particularly is directed to'trucks of this type having a lowerwheeled frame providedwith any suitable type of steering means, and-having-an upper platforrrror'frame which is adapted to be raisedand lowered-with respect to the lower frame, the upper frame or platform being adapted for'picking tote boxes andthe like from the floor, and then being raised'in position in -order that the truckmay transport the load.

to any desired point.

The present invention broadly contemplates an improved and simplified design of truck, and in the main is a animprovement overgtrucks of the type disclosed in my prior patents, Nos; 1,707,971, 1,773,935 and '1,303,E88, cfApril 9, 1929, August'26, 1930, and May 5, 1931,- respectively.

One of the main features of the present invention is that the truck of the present invention v requires no release checkfor holding theupper frame or platform in raisedposition, although provision can, be made-for the attachment of such check means if it is desired by the operator; However, the truck is designed for safe-open 2c ation without therelease check, by the provision of'means whereby thetruck may be moved 'under theload, and theplatform raised into load sup=- porting position and then 'retained'in thisposition automatically until released by operation 0f a foot treadle or the like by theoperator.

After the operation of the foot treadle, it is-nec' .essarythat the handle which controls the rais-- ing and lowering of the platform must be lowered to what would correspond to'the' end of theing and lowering movements, while at th'e same time preventingany removalof this frame 'from the lower frame. l

Another feature of the present invention: is 50 :theprovision of improved. latching means which is automatically engaged to latch the platform: in raised position'as the platform is raised by the steering handle, which latching means maybe employed with or. without thev usual typeof re- 55-lease check. i

7 verted U, and is. provided withs'a centrallyqloe yoke carriediby theypedestalv or crossheadis pro:

' In connection with the-latching means, one of:

. tl1e-'main advantages" of thepresent'construction is the provision of "an arrangement whereby-the latching means is engaged by a latch pin.

carried 'by theupper frame '01 platform in such manner that it positively secures" the pin in latchecl'positiontand prevents, any accidental dislocation thereotfl Thelatching means 'of' the y 7 present invention is 1 releasable only-when the lowing 'detaileddescription, which, takenin conjunction-with the accompanying drawings, will disclose tofthoseskilled in the art the particular construction and operation" of apreferred form ofthepresentinvention. a

In the drawings:

Figure -1 is'a side elevational view ofthe-la'tching mechanism employed in" the present invention; I I t Figure- Zis a top *elevational view of the detail parts of the latch control;

' Figure 3 isan enlarged'sideelevational viewof the -latching mechanism, showingits operationwith the platformin raised position;

Figure-4 is a sectional view, taken'transversely across the rear axle-of the truck, showing the improvedrear axleconstruction; and I Figure "5 is aperspective view 'of'one of the supporting crankarms shown in Figure 4.

{Referring now in detail to the-drawings, in Figure- 1 'I' have provided'a lift truck of more or lessconventional" design comprising a, lower frame '5, having" a crossliead at its front end cjournaling the steering shaft 6,- and having a '9 are carried. by the rear/shaft l;

Supported at the front end. of. the :frame 5 is acrosshead. I0, which is: in the. form of anuin-- cated bearingzfor'thevvertical pivot of the steer-- ing yoke which supports the shaft 6 and the, steering, Wheel 8., Either one, or, twosteering.

Wheels may be;provided.-

Thejournal bearingplatezlll fortheisteeringu to each other.

other of the longitudinal axis of the truck, to

steer the wheel or wheels 8.

Mounted upon the lower frame 5 is a lifting frame it, having side members which overlie the side members of the supporting frame 5. Near the front end thereof the side members are connected by a cross beam H, which is preferably in the form of a channel-shaped member to the web surface of which is secured an angle member l3 forming a platform stop for'limiting the forward position of the platform or load which is to be carried upon the frame I6.

The forward end of the side members forming the frame it have pivotal cormection at 18 with suitably disposed links for guiding the raising movement of the upper frame or platform. The links 25 are pivoted at their lower end to the side members of frame 5 adjacent the rear end portions 22 of the crosshead It, as indicated at 23.. By pulling forward on the. lifting frame, it will be apparent that the platform It will be raised by the clockwise rotation of the links 20 about the pivot 23, the platform moving upwardly and forwardly.

V-shaped, and the separated rear ends of the yoke are adapted to pass through the vertical flange 25 of the cross beam I'I. These ends carry rounded heads 27 as shown in dotted lines in Figure 1, which are secured in place by suitable nuts screwed onto the rear ends of the yoke. The-heads 2'! bear in the angle formed in the cross beam ll, and form rocker bearings for the yoke, to permit its forward end to swing slightly, thereby preventing binding during the operation of raising or lowering thelifting frame.

.At its forward end, the yoke 25 carries a double link 28, comprising portions 29 and 30 rigidly connected together and disposed at right angles The portion 29 has a horizontally "directed opening 32 therein which receives the end of the yoke 25, while the portion 30 has a vertically directed opening which is adapted to receive a shackle member 33 pivoted on the transverse pivot 14 which supports the operating handle l5, and which is in the form of a bellcrank, the opposite end away from the pivot I4 being tapered and provided with a lug or tooth 34 clockwise direction about the pivot I 4, which results in forward movement of the shackle member 33, and consequently a forward and upward pull upon the yoke member 25. This exerts a corresponding forward and upward pull on the frame members constituting the platform It, and the platform 15 moves forwardly and upwardly about the pivot 23 and the pivot formed by the rear axle shaft 1.

Considering now Figures 2 and 3 in detail, the forward end of the lifting frame I6 is provided intermediate the sides thereof with a pair of forwardly extending parallel .strips 40 and 42, which may be welded or otherwise suitably secured thereto, and which at their forward ends are provided with means for supporting the latch pin 43-therebetween, the pin being held against displacement by means of the cotter key 44 as shown in Figure 3.

Mounted upon the pedestal support or cross head If], which is provided with the rearwardly extending spaced cars 45, is the latching mechanism shown in detail in Figures 2 and 3. Supported at the outer ends of the ears 45 is the pivot pin 45, which is adapted to receive therebetween atreadle member generally indicated at 41, and of generally Z-shape. The treadle member 47 is provided with a forwardly extending treadle portion 48, and with rearwardly extending arms 49 carrying pivot pin 55 at their outer ends.

Pivoted on the pin 50 between the arms 49 is the latching jaw is provided with a rearwardly extending portion 56 mounted on the pivot pin 46. The latching jaw 55 is provided with a downwardly curved tip portion 51 adapted to form a camming surface for guiding the latch pin 43 upwardly along the upper surface of the jaw 55, and is also provided with a notch or latch retaining recess 58 adapted to receive the latch pin 43. 1

The jaw 55 is provided with a downwardly projecting boss 59 at its lower side, having a recessed opening 60 forming a seat receiving one end of the spring 62, theopposite end of the spring 62 being biased in a seat 63 formed in a projecting boss 54 of the treadle member 4'1. By reason of this spring connection, the treadle member 41 tends to rotate in a counterclockwise direction with respect to the pivot 46, While the jaw member 55 tends to rotate in a clockwise direction. As a result, the edge 54 of the member 52 is pressed downwardly into pressure engagement with the upper inclined surface of the jaw mem- 4! abuts against the back surface of the cross head I B. In such normal position of the latch assembly, the parts thereof are so disposed, relative to the path of travel of thelatch pin 43 on the lifting frame, that during the lifting operation this latch pin moves upwardly over the rear surface 51 of the latch jaw 55 and into engagement with the rear edge of the locking member 52.

Referring now to the operation of the latch mechanism, the lifting frame is raised by a downward stroke of the handle l5, and in such lifting movement the latch pin 43 on the lifting frame swings upwardly over the'rear surface of the latch jaw 55 and- -into engagement with the rear edge of the locking member 52, as above deexerts a cammingpressure onthelupper surface of the jaw member 55; thereby causing a relative of the member 52., thereby insuring that 'saidlock ing member 'willlbe pressedv against thelatch pin: when in this final'position through the action of the. spring fiilt'endingtoi-force the membersl52 15 lftherhandleglesis nowrlowered to a position scribed; Continued ,forward-motionnof the: latch: pin' lii in-ziabutment with'the rear edge of. said.

locking member. 52!..causes theelatterato swivel forwardly: or; inwardly: around its pivot 5D in a.

counterclockwise direction. In-this inward swinging motion, the lowerlip 551ofthemember52.

spreading. motion between thetreadlelmember 41 and said latch member 55; andaccoinmodating continued inwardamotionof the locking member 52 toward the final position indicated approximately in .dott'ed'lines in Figure 3. This-relative spreading; motion is; yieldably. opposed;,by'the spring 62. In the final .movementof theparts, the latch pin ddsrides beyond 'theshoulder 61 of thelatchingjaw 5.5:: so. that thisz jaw member" can swing. upwardly underthe -.action1of the.

. spring. fifand hcokits latchingrecess 58.around the back. side. of the latching-pin 43: Also, the locking member52;assumes the final position: indieatedzin dotted lines withuthe .tip end 65' thereof bearing against the upper lateral surface of thelatch pin 43 The'locking member 52-is held in this position,fpressed againstllthe pin 43, by the pressure ofthe spring'fl, andalso'bythe weighted: portion 53 of said member, which tends to rotate. the ,latter in a: clockwisesdirection about the pivot 58. It is alsoto be notedIthat the arms 59 of the member 4! areprovidedwith stop.

surfaces 66 which-are abuttedbyfthe weighted portion 53x0 limit the counterclockwise rotation and 55 toward each otherp' I.

In this position, with thelatoh pin43 disposed in the notchior recess 58 of the jaw .member 55;: andthe member 52 bearing against the upper surface thereof,':no disengagement of the pin 43* from: the latching, means is possible, even though the lifting handle it: be oscillatedv rearwardly,

tending. to allowthe member -l6 to lower under I gravity, due to-the'release .of pulling engagement on the yoke-'. As a -result,'regard1ess of move-," mentof the handle i5into any upper, lower,v or, sidewise position, theiplatform remains latched'in, raised position, and the. truck'can be moved'to any desiredlocation without the. danger of lower ing the platformv or upper frame due to movement of the handle 15. When it is desired to lower the platform N5, the operator must first. step on the treadle member 48. This produces "clock-;- 7 wise rotation of the treadle member, andresults in anupward movement of the arms 49. 1 As a result, the pivot pin is lifted upwardly, and due to the'co-unterbalance 53 on the member 52,-

the member 52 also rotates ina clockwise direction and returns tolits normal position with the snrfacefi l thereof 1 engaging the upwardly inclined surface of the jaw member 55, andoverlying the jaw member and'the recess 48.

- When the treadle member has been thus .actu '-;:;.ated,-and the memberEZ restored to its'normal' position, there is no means engaging the upper surface of the pin 43restrainingit within. the notch '58. f However, due 'to the fact that the notch 58 has a curved rearward surface which eX-- v tends over andbeyondgthe center of the pin 43, the platform still ;will not be capable of being loweredby itself, but the latching means is nowconditioned for release of the pin 43 upon movement. of the handle. 15.

corresponding: to the end of. the-lifting stroke, theshandle upondepression. will allow the entire latching assembly to-swivel about the. pin 46;.the-

rear end of the member 55, indicated at ELmoving downwardly in a counterclockwise direction withrespect; tothe. pivot 45. "This moves. the notch .58 downwardly, until the center of the pin 43-moves abovethe lip of the notch 58,indicated at .61.: As a:resu1t,.the pin 43 can then move outwardly between themembers and 52, along the overlying surfaces thereof, andthe platform or upper lifting frame can be loweredunder controlrof the :handle l5.v "Thus, as the handle is slowly released, the pin 43 pulls outwardly b etween the ,member 55 and s2, separating these members, and-permittingthe frame or platform IE to move downwardly under gravity and under" means for release'off the: pin upon further move ment of *the. handle Hi. The construction is relatively simple,- composed for the most :part of castings, which ,can be easily assembled, and

whichrequire no accurate machining operations: I

Thus a simplified and economical design of latchingmechanism'is. provided which is positivein operation and employs relatively few moving parts.

connection with: the rear axle construction shown in Figure l, the present invention:contemplates'a construction which, .while of the gener'alform used inpreviouslift trucks of this design, has incorporated therein-several differences which not only reduce the manufacturing; cost, but; 1WhiCh produce abetter and. stiudier construction.-

I In this embodiment of the invention, therear, links and the upperpart'ofrthe rear axle arezem bodied in'onefmembery The "axle shaft 1, which has the wheels z'journaledxthereon.adjacentopposite ends thereof, is itself journaled for rotationin the side members Ill and 12 of the lower;

frame 5. v Secured 13, formed of flat strips of metal bent-into U- shape, and having. the extending parallel'portions 14 adapted to be clamped tcgetherbby means of the bolt 15 passing therethrough. This frictionally clamps'the member E3 ;to theaxle shaft,

and'if desired the shaft mayv be flattened at one portion "to. receive. theflatted surface of the bolt 15 in order to -positively prevent rotation of the member It with respect to the shaft. Theshaft,

of course, is freeto rotate with respect to wheels 9. Mounted upon the external. surface of'the U-shaped portion of the member. 13 is a crank arm 16, comprisinga right-angle member formed of stock turned at one end to provide areduced projecting' stud ii, and bent cold in a die to produce the :right angle form shown. The opposite end of the member 16 is welded or otherwise-suit ably secured to themember 13, a indicated at '13: The extension'lllof the shaft or crank por tiOn-TB of-the axle construction enters throng-hf Considering now in detail Figures4 and..5 ,in

to -'the axle shaft 1 7 inwardly of the frame members 12 are a pair of 'U-shaped clamps the upper end of alink lllmounted at itsopposite end on the shaft 1, and then extends into the side'member liil'ofth'e supporting or lifting frame I63. Breferably' the projection 1! ofthe member 76 extends flush with the outer lateral surface of the side frame members 88, in order to eliminate any projections or thevlike on the sides of the upper frame. 4

It will be apparent that by this construction the upper frame I6 is positively connected to the lower frame through the members 16 and the clamping portions 13 thereof, and also that the load on the platform or upper frame it is supported by these members which bear, on the horizontally extending outturned portions, within the angle formed by the angle member 82 secured transversely between the side frame members 8i].

It will therefore be apparent that upon lifting of the frame IE by means of the handle IS, the rear end of the frame will move upwardly and forwardly about the axle l as a center, and any load upon the frame will be supported by. the crank arms I6. By the provision of the link 19, the free ends of the arms 16 are prevented from bending inwardly, and in efiect a substantially U-shaped support comprising the members 73, 7S and 19 is disposed about each of the wheels and engages in the anglebearing member 82 at the rear end of the frame lEfor supporting the same as it is raised in position.

Of course,jif desired the members 16 and 13 might be formed integral as a casting, clamped to the axle shaft in the same manner, but I have found that the welding of the stock 16 to the bent strip'TS serves the same purpose and is equally as effective for supporting the load on the platform during the raising movement.

It is thus believed obvious that the axle construction herein provided is considerably simplifled over-the constructions shown in my aforementioned patents, and also possesses distinct advantages of design and construction as far as ease of manufacture and economy isconcerned.

'While I am aware that various changes in the construction, design and fabrication of the various parts'constituting the features of the present invention are possible, I do not intend to limit the present invention to the specific illustrated embodiment thereof, but only in so faras defined by the scope and spirit of the appended claims.

I claim:

. 1. In combination, a lift truck comprising a frame, a platform carried by said frame, means including a handle pivoted at onev end of said frame for raising and lowering said platform, a latch pin carried by said platform, latching means pivotally mounted on said frame for receiving and retaining said latch pin when said platform is raised including means for locking said pin in '2. In combination, a lift truck comprising a frame, a platform carried by said frame, means including a handle pivoted at one end of said.

frame for raising and lowering said platform, a latch pin carried by said platform, latching means pivotally mounted on said frame including means for receiving and locking said latch pin when said platform is raised, and means for releasing said locking means while leaving the said latching means in operative position, said latching means beingconstructed and arranged.

to then release said pin upon a further lift of said platform by said raising means, said raising means being effective to release said pin only upon prior actuation of said releasing means.

3. In combination, a lift truck comprising a 7 frame, a platform carried'thereby, means including a control handle mounted on said frame for raising and lowering said platform with respect to said frame, latching means operable upon raising'of said platform for locking said platform in raised position, and means operable independent- 1y of said raising and lowering means for setting said latching means in position tov permit release of saidplatform upon a further lift of said plat form by said raising means.

4..In, combination, a lift truck comprising a wheeled truck frame, a platform carried thereby, means for moving said platform upwardly and longitudinally with respect to said frame into raised position, latching means for retaining said latching means comprising a support, a first jaw.

member pivotally mounted on said support, a treadle member pivoted coaxially of said jaw member on said support andincluding arm portions extending over said first jaw member, a second jaw member pivotally mounted between said arms and normally overlying the upper surface of said first jaw member, a latch pin retaining recess inthe upper surface of said first-jaw member normally protected by said second jaw member, spring means between said first jaw member and' said treadle member urging said jaw members into engagement, said second jaw member being rotated by entrance of the latch pin between said jaw members and into said recess into a position retainingsaid pin in said recess, and means on saidsecond jaw member operable upon rotation of said treadle member moving said arms away from said first jaw member for restoring said second jaw member to its normal position overlying said upper surface of said first jaw member. a

6. Latching means of the class described for holding a load supporting platform in raised position, said platform having a latch pin, said means comprising a pair. of latching jaws, spring means normally urging said jaws together, one of said jaws having a latch pin retaining recess and the other of said jaws-being independently rotatable with respect'tosaid one" jaw, means for raising said, platform whereby said pin is forced between said jaws and engaged in said recess, said other of said jaws being rotatedinto position to hold saidpin in said recess, and means pivoted coaxially of said one jaw for restoring said rotatable jaw to initial position independently of movement of said platform.

7. Latching means for supporting the lifting platform of a lift truck in raised position comprising a pair of latch members normallymaintained in superposed position, the upper latch member being pivotally mounted for movement independently of the lower memberya latching recess in oneof said-members adapted to receive platform operating means will permit the lower-.

alatch' pin carried by saidplatform' and forced between said members when the platform is raised,- the;other of said members being pivoted into overl 'ng engagement with said pin by moves ment of-" said' pin into said recess, means for restoringsaid other of saidlnernbers to' normal j superposed position, andmea'ns operable when said platform is fto be lowered to enable said latchingmembers to rotateinto position to disengage said pin from said'recess, said pin moving outwardly between said'memb'ersupon lowering of said platform.

SI'ThecG'mbin 'ti'on,'with a lift truck having a platform adapted to be raised and lowered, and operating means for raising and lowering said platform, of a latch pin carried by said platform,

a pair of latching membershaving a pin-retaini'ng recess in one of said members,'the other of said members being pivotally mounted in position normally overlying said recess, said pin rotating the other of said members out of overlying position and entering said recess when said platform is raised, spring means urging said other of said members into position to hold said pin in said recess, and means operable independently of said platform-operating means for restoring said other of said members into normal overlying posi tion, so that a further operation of said platform operating means will first permit said latching members to rotate into a position to release said pin from said recess, and upon release 'of said ing ofsaid platform and the simultaneous move- -ment of said pin outwardly from between said jaw members. r

9'. Latching means for a lift truck having a lift-f ing platform, comprising a pivotally mounted latch member having a latch-pin receiving recess,

pivotally mounted means normally overlying said recess, spring means normally urging said'lastnamed means against said latch member, a latch p in carried by said platform and adapted to rotate said pivotally mounted means away ,from said i latch member and to engage in said recess upon raising of said platform, said pivotally mounted means being spring pressedagainst said pin after said pin engages in said recess, means for raising said pivotally mounted means away from said pin to restore said pivotally mounted means to its normal position overlying said recess, and means operable when said platform is to be lowered for releasing said pinfrom said recess and into position to pass outwardly between said latch memher. and said pivotally mounted means as the platform is lowered.

10. In a lift truck of the class described, a frame, a platform mounted on said frame, a holding latch pin at one end of said platform, a latch having a latching recess and pivotallyr'nounted on said frame adjacent said end of said platform, a treadle member conjointly pivoted with ,said

latch and having a portion overhanging said latch,.- a- .locking member pivotally supported by said overhanging portion and normally overlying said recess, spring means normally urging said locking member into said latter position, and

means for raising said platform and movingsaid latch pin against said locking member to pivot:

said locking member into position above said recess" to permit'saidpin to enter said recess, said spring means'urging said locking member into en- 1 gagement with said pin after said pin has entered said recess.

In a'lift truck having a truck frame, an axle in one of said offset studs extending""transverselv through' said frame, wh'eels journaled at the opposite ends'of said axle, I l 1 a'platform carried bysaid frame and means for 'guiding and supporting said platformfiwith respect to saidaxle comprisingrock arms rigidly secured r to said axle adjacent said wheels, integral outturnedfiends on saidarmshaving reduced journal portions links between the ends of said axle and said platform, and-means insaidlinksjand said platform for receiving the journal portions of said arms. I a. r v

12. Arear axleconstructionfforla:lift truck versely in said lowerframe, wheels on said shaft adjacent opposite ends thereof, links, mounted; at one end on the ,ends of said shaft, and rock armssecured to said shaft between said wheels and including end portions iournaled in. said; upper frame and in the opposite ends of said links.-

'" ofithetypahaving' an upper framed-and a. lower ffram'e, comprising an axle shaft journaled trans- 13. Means for supporting and guiding the upper frame of alift truck with respect to" the lowerframe, comprising an axle shaft journaled in thelower frame, wheels mounted on the ends of said shaft and rotatable thereon, an angle bearing member extending transversely "across the upper frameat one end thereof above said shaft,- vertical side flanges forming a part of said 3 upper frame, and U-shaped means having the I ends thereof secured to said axle shaft on opposite sides of. each'of said wheels and having bearing engagement with said angle membensaid means having laterally extending stud portions engaging said side flanges at'opposite ends of said bearing member to connect said upper frame therethrough .to said shaft. I

14. Means for supporting andguidingthe upper. frame Ora 11a truck with respect to the in the lower frame, wheels journaled 'onthe ends lower frame, comprising an axle shaft journaledfl 40 of said shaft, an anglebearlng member extending 1 transversely across the upperi frame; at one end thereof above said shaft, sidefiangesforming-the edges of said upper frame, and U-shaped means havingthe ends thereof mounted on said axle having bearing engagement within'said angle member, said means having laterallyjoffset studs engaging said side flanges'to connect said upper frame therethrough to said shaft, each of said and having itsoppos'ite end passing through the oppositeend of said link member and terminating 15., In combination, a lift truck respect to said frame,,latching means on said frame including a pair of pivotally mounted latching lmembers, azlatch pin carried". by said platform and movable between said members upon raising of said platform into latched position therebetween, and means for pivotingone of said latching members into unl'atched position while said other latching-member retains said pin Y.

against release, said latter latching member bev ingfconstructed and arranged to then release said'pin upon a further .lift of the platformby said raising means.

16. me. lift truck of the class described, the

,7 combination of a main frame mounted on rear wheels and onalaterally steerable front wheel, a lifting frame'mounted .on said main frame for shaft on opposite sides of each .of said wheels and 56 U-shaped means comprising a planar link mem- -ber mounted at one end on' said shaft, and an I L-shaped bracket secured-at one end to said shaft back side of which is defined a latching recess, a latching pin carried by the other of said frames and adapted to have hooked engagement within saidlatching recess whereby to establish a latched relation capable of retaining said lifting frame in elevated. position, and a locking member movable into position to block relative separation between said latching pin and said latching recess so as to prevent accidental lowering of said lifting frame irrespective of the movement of said handle into different positions, said locking member being manually releasable when it is desired to lower said lifting frame through the instrumentality of said handle.

ARTHUR M. BARRETT. 

